DMARDs Flashcards
What is the mechanism, method of administration and side effects of methotrexate?
A dihydrofolate antagonist that interferes with the metabolism of folate and suppresses certain components of the immune system
Methotrexate prescribed once a week and often prescribed with folic acid to be taken on other days
Side effects:
Mouth ulcers and mucositis
Liver toxicity (deranged LFTs)
Pneumonitis
Pulmonary fibrosis
Bone marrow suppression causing pancytopenia (low counts of RBCs, WBCs and platelets) and immunosuppression
It is a teratogenic - avoid prior to conception in men and women
In overdose, use folinic acid as rescue therapy
What is the mechanism and side effects of leflunomide?
Suppress immune system by interfering with the production of pyrimidine. Pyrimidine is an important component of RNA and DNA
Side effects: Mouth ulcers and mucositis Hypertension Alopecia Pneumonitis Peripheral neuropathy Hepatotoxicity Bone marrow suppression causing pancytopenia and immunosuppression It is a teratogenic – avoid prior to conception in men and women
What is the mechanism and side effects of azathioprine? What drug can it interact with to cause azathioprine toxicity?
Azathioprine is metabolised to the active compound mercaptopurine, a purine analogue that inhibits purine synthesis. A thiopurine methyltransferase (TPMT) test may be needed to look for individuals prone to azathioprine toxicity
Thought to be safe to use in pregnancy
Side effects:
Nausea and vomiting
Pancreatitis
Increased risk of non-melanoma skin cancer
Bone marrow suppression causing pancytopenia and immunosuppression
May interact with allopurinol and lead to azathioprine toxicity, hence, lower doses of azathioprine should be used
What is the mechanism and side effects for sulfasalazine?
Works as an immunosuppressive and anti-inflammatory medication
Mechanism unclear but may be related to folate metabolism
Thought to be safe in pregnancy
Side effects:
Haemolytic anaemia
Abnormal LFTs
Azoospermia – male infertility (avoid in young men)
Bone marrow suppression causing pancytopenia and immunosuppression
What is the mechanism and side effects for hydroxychloroquine?
Traditionally an anti-malarial medication
Acts as an immunosuppressive medication by interfering with Toll-like receptors, disrupting antigen presentation and increasing the pH in the lysosomes of immune cells
Thought to be safe in pregnancy
Side effects: Photosensitivity which causes a rash Haemolytic anaemia Retinal toxicity – reduced visual acuity Nightmares Bone marrow suppression causing pancytopenia and immunosuppression
What is the mechanism and side effects of Anti-TNF?
TNF is a cytokine involved in stimulating inflammation. Blocking TNF reduces inflammation
Adalimumab, infliximab, golimumab and certolizumab pegol are monoclonal antibodies to TNF
Etanercept is a recombinant human protein that binds TNF to the Fc portion of IgG and thereby reduces its activity
Side effects:
Vulnerability to severe infections and sepsis
Reactivation of TB and hepatitis B
Due to side effects, patients have to undergo extensive screening including bloods (to rule out infection) and screen for latent TB (as these drugs can impair long term TB suppression and reactive it)
What is the mechanism and side effects of rituximab?
Monoclonal antibody that targets the CD20 protein on the surface of B cells. This causes destruction of B cells
Side effects: Vulnerability to severe infections and sepsis Night sweats Thrombocytopenia (low platelets) Peripheral neuropathy Liver and lung toxicity
